There are three key areas of focus in data science interviews: business acumen, communication/data storytelling ability, and technical intuition.
Every interview is also an opportunity to practice and improve your soft skills
Understanding your own market value and confident communication skills are the key to successful salary negotiations
In your first 90 days, go around and meet every single person that you think is important and then ask them who else you should meet. Then just keep on meeting people. Then try to add some business value extremely quickly. This is not very difficult because there are a lot of small things that people overlook and just don't do, like documentation. Documenting something that you find out isn't documented in your onboarding can provide huge value right away.
The key to successful salary negotiation is understanding your own market value. Generally, companies will hire you for the price that it costs to replace you. That's the brutal nature of hiring in general, and understanding your market value is the key to taking that to your advantage.